03.11.2019
How many phenotypic groups will be obtained with. Chlamydomonas, which is a genus of unicellular green algae from the Chlamydomonas family, is an example of a level of organization. How many types of gametes will AaBb get
At dihybrid crossing
- two signs are studied, for example, "white short hair";
- two pairs of (alternative) genes, eg AaBb x AAbb.
In a dihybrid cross, genes A and B can be inherited independently or linked.
Independent Inheritance
If genes A and B are in
- different chromosomes;
- different couples chromosomes;
- non-homologous chromosomes;
- different pairs of non-homologous chromosomes (all this is the same);
then they are inherited independently, according to Mendel's III law (the law of independent inheritance): "Splitting on each pair of features occurs independently of other pairs of features."
The cytological basis of independent inheritance is the independent divergence of chromosomes in anaphase I of meiosis.
Splits characteristic of independent inheritance in dihybrid crosses
1) No splitting (all children are the same) - two homozygotes AABB x aabb (or AAbb x aaBB) were crossed.
2) Splitting 9:3:3:1 - two diheterozygotes AaBb x AaBb were crossed (Mendel's third law).
3) Splitting 1:1:1:1 - a diheterozygote and a recessive homozygote AaBb x aabb were crossed (analyzing cross).
Linked inheritance
If genes A and B are located in
- one chromosome;
- one pair of chromosomes
- one pair of homologous chromosomes;
then they cannot separate independently, there is a linked inheritance according to Morgan's linkage law: "Genes located on the same chromosome are inherited together".
All genes on the same chromosome form a linkage group. The number of linkage groups is equal to the number of chromosomes in the haploid set (the number of pairs of homologous chromosomes).
How many types of gametes will AaBb get:
- with independent inheritance - 4 types of gametes (AB, Ab, aB, ab) 25% each
- with full clutch only 2 types of gametes (for example, AB and ab)
- with incomplete clutch(due to crossing over) - 4 types of gametes, but not 25% each (not equally).
Choose one, the most correct option. If the genes responsible for the color and shape of pea seeds are located on different chromosomes, then the law manifests itself in the second generation
1) independent inheritance
2) linked inheritance
3) feature splitting
4) dominance
Answer
Choose one, the most correct option. The number of gene linkage groups in organisms depends on the number
1) pairs of homologous chromosomes
2) allelic genes
3) dominant genes
4) DNA molecules in the cell nucleus
Answer
Choose one, the most correct option. What types of gametes are formed in an organism with the AaBb genotype when dominant genes are linked
1) AB, ab
2) Ab, aB
3) AB, Ab, aB, ab
4) Aa, Bb
Answer
RATIO OF PHENOTYPES IN THE ANALYSIS CROSSING OF A DIHETEROZYGOTE
1. Determine the ratio of phenotypes in the offspring when crossing a diheterozygous pumpkin plant with white round fruits and a dihomozygous plant with yellow elongated fruits ( White color And round form fetus dominant traits) with complete dominance and independent inheritance of traits. Write down the answer in the form of a sequence of numbers showing the ratio of the resulting phenotypes, in descending order.
Answer
2. Determine the ratio of phenotypes in offspring during dihybrid crossing of an organism homozygous for both traits (aabb) with a diheterozygous organism. The genes are not linked. Dominance is complete. Write down the answer in the form of a sequence of numbers showing the ratio of the resulting phenotypes.
Answer
3. Determine the ratio of phenotypes in offspring in the analysis of crossbreeding of a diheterozygous organism with complete dominance and independent inheritance of genes. Write your answer as a sequence of numbers arranged in descending order.
Answer
4. Determine the ratio of phenotypes in offspring in the analyzing crossing of a diheterozygous black crested chicken with independent inheritance of traits. Write your answer as a sequence of numbers.
Answer
RATIO OF GENOTYPES IN THE ANALYSIS CROSSING OF A DIHETEROZYGOTE
1. Determine the ratio of genotypes in the offspring during analyzing crosses, if the genotype of the parent is AaBb with complete dominance and independent inheritance of traits. Write down the answer in the form of a sequence of numbers showing the ratio of the resulting genotypes (without additional characters).
Answer
2. Determine the ratio of genotypes in the offspring obtained by analyzing crosses, if the genotype of one of the parents is AABb. Write your answer as a sequence of numbers in descending order.
Answer
3. When heterozygous tomato plants with red and round fruits are crossed with individuals that are recessive in both traits (red A and round B are dominant traits), offspring with the genotypes AaBb, aaBb, Aabb, aabb will appear. Write down the ratio of these genotypes as a sequence of numbers in descending order.
Answer
RATIO OF PHENOTYPES WHEN CROSSING TWO DIHETEROZYGOTES
1. What ratio of phenotypes will be obtained by crossing two diheterozygotes with complete dominance and independent inheritance of genes? Write your answer as a sequence of numbers in descending order.
Answer
2. Determine the ratio of phenotypes in offspring in a dihybrid crossing of two heterozygous organisms with complete dominance. Write down the answer in the form of a sequence of numbers showing the ratio of the resulting phenotypes, in descending order.
Answer
3. Determine the ratio of phenotypes in the offspring when crossing females and males with AaBb genotypes, given that the genes are not linked to each other and complete dominance is observed. Write down the answer in the form of a sequence of numbers showing the ratio of the resulting phenotypes, in descending order.
Answer
4. Determine the ratio of phenotypes in offspring when crossing two Drosophila diheterozygotes with a gray body and a normal wing shape (the genes are in different pairs of autosomes). Write your answer as a sequence of numbers arranged in descending order.
Answer
RANDOM PROBLEM, DETERMINE PROBABILITY
1. In beans, the yellow color of the beans dominates over the green, and the black color of the seeds dominates over the white. Determine the probability (in %) of the appearance of bean plants with green beans and white seeds when a dihomozygous plant with yellow beans and black seeds self-pollinates. Write down the correct number for your answer.
Answer
2. A person has brown eyes (A) and one of the forms of myopia (B) - autosomal signs. Determine the probability (in %) of the birth of a blue-eyed child with normal vision, if his parents are brown-eyed with normal vision (homozygotes for both pairs of traits). Write down only the appropriate number in your answer.
Answer
3. A woman with long eyelashes and wide eyebrows, whose father had short eyelashes and narrow eyebrows, married a man with dominant traits homozygous for both alleles, a child with long eyelashes and wide eyebrows was born in the family. What is the probability (in percent) of the birth in this family of children with the same phenotype as the mother, with complete dominance and independent inheritance of traits? Write only the number as your answer.
Answer
4. What percentage of children will have brown hair and normal length legs if the father is Aabb and the mother is aaBb (A is black hair, a is brown hair, B is short legs, b is normal legs).
Answer
Choose one, the most correct option. Scheme AABB x aabb illustrates crossing
1) monohybrid
2) polyhybrid
3) analyzing dihybrid
4) analyzing monohybrid
Answer
Choose one, the most correct option. When heterozygous tomato plants with red and round fruits are crossed with individuals recessive in both traits (red A and round B are dominant traits), offspring with the genotypes AaBb, aaBb, Aabb, aabb will appear in the ratio
1) 3:1
2) 9:3:3:1
3) 1:1:1:1
4) 1:2:1
Answer
Choose one, the most correct option. When crossing Drosophila with a gray body and normal wings and Drosophila with a dark body and rudimentary wings, the law of linked inheritance is manifested, since the genes responsible for these traits are located in
1) mitochondrial DNA
2) different pairs of chromosomes
3) one pair of chromosomes
4) sex chromosomes
Answer
Choose one, the most correct option. In dihybrid crossing (unlinked inheritance), individuals with dominant and individuals with recessive traits in F1 split according to the phenotype in the ratio
1) 9:3:3:1
2) 1:2:1
3) 3:1
4) 1:1:1:1
Answer
Choose one, the most correct option. The genotype of one of the parents will be AaBb if, during analyzing dihybrid crossing and independent inheritance of traits, splitting in the phenotype in the offspring is observed in the ratio
1) 1:1
2) 3:1
3) 1:2:1
4) 1:1:1:1
Answer
Choose one, the most correct option. Genes are always inherited together
1) recessive
2) allelic
3) dominant
4) closely linked
Answer
HOW MANY TYPES OF GAMETES WITH FULL LINKAGE
1. How many types of gametes does a diheterozygous individual form with full linkage of the studied genes?
Answer
2. How many types of gametes does an individual with the AaBb genotype form with full linkage of the studied genes? Write your answer as a number.
Answer
3. How many types of gametes does an individual with the AaBb genotype form if it is known that non-allelic genes are linked and there was no crossing over? Write your answer as a number.
Answer
HOW MANY TYPES OF GAMETES IN INDEPENDENT INHERITANCE
1. How many types of gametes does an individual with the AaBb genotype form with independent inheritance of traits? Write your answer as a number.
Answer
2. How many types of gametes does a diheterozygous individual form with independent inheritance of traits?
Answer
3. How many types of gametes does an individual with the AaBb genotype form in case of gene linkage disruption during crossing over? Write your answer as a number.
Answer
4. How many types of gametes does a diheterozygous individual form when the linkage is broken by crossing over?
Answer
How many types of gametes do individuals with the AaBB genotype form? Write down only the appropriate number in your answer.
Answer
How many types of gametes does a dihomozygous individual form? Write down only the appropriate number in your answer.
Answer
HOW MANY GENOTYPIC GROUPS
1. How many different genotypes will the offspring get when analyzing the crossing of an organism with the AaBB genotype (complete dominance and independent inheritance of traits)? Write down only the number of genotypes in your answer.
Answer
2. How many genotypes in offspring can be obtained in an analyzing cross of a tomato plant that is dihomozygous for dominant traits of fruit shape and fruit color with independent inheritance of traits? Write your answer as a number.
Answer
3. How many different genotypes can be obtained by self-pollination of a tomato plant, homozygous for the recessive trait of fruit shape and heterozygous for fruit color, with complete dominance and independent inheritance of traits? Write your answer as a number.
Answer
4. How many different genotypes can be obtained by crossing an oat plant homozygous for the late-ripening gene and heterozygous for the normal growth gene with an oat plant heterozygous for the late-ripening gene and homozygous for the giant growth gene with complete dominance and independent inheritance of traits? Write your answer as a number.
Answer
HOW MANY PHENOTYPICAL GROUPS
1. How many phenotypic groups will result from self-pollination of a heterozygous pea plant with yellow smooth seeds? Write down only the appropriate number in your answer.
Answer
2. How many different phenotypes can be obtained in descendants in an analyzing cross of a tomato plant, diheterozygous for the traits of the shape and color of the fruit, with independent inheritance of traits? Write your answer as a number.
Answer
3. How many phenotypic groups will be obtained by crossing two dihomozygous individuals with different phenotypes (genes are located on different chromosomes). Write down only the appropriate number in your answer.
Answer
4. How many different phenotypic groups can be obtained by self-pollination of a tomato that is homozygous for the recessive trait of fruit shape and heterozygous for fruit color with complete dominance and independent inheritance of traits? Write your answer as a number.
Answer
5. How many phenotypes will appear in hybrids when a diheterozygous pea plant is crossed with a plant homozygous for recessive traits, if the traits are inherited independently of each other, and dominance is complete? Write down only the appropriate number in your answer.
Answer
Choose one, the most correct option. With dihybrid crossing and independent inheritance of traits in parents with AABb and aabb genotypes, splitting is observed in the offspring in the ratio
1) 9:3:3:1
2) 1:1:1:1
3) 3:1
4) 1:1
Answer
Choose one, the most correct option. When crossing individuals with AaBb genotypes with AaBb (genes are not linked), the proportion of heterozygotes for both alleles in the offspring will be
1) 0,75
2) 0,5
3) 0,25
4) 0
Answer
PHENOTYPE RATIO AT FULL LINKAGE
1. Determine the ratio of phenotypes in offspring in a dihybrid crossing of two diheterozygous organisms. Dominant and recessive genes are linked in pairs. Dominance is complete. Write down the answer in the form of a sequence of numbers showing the ratio of the resulting phenotypes.
Answer
2. Determine the ratio of phenotypes in the offspring during the analyzing crossing of a diheterozygous hamster with full linkage of genes. Write your answer as a sequence of numbers arranged in decreasing order.
Answer
RATIO OF GENOTYPES IN FULL LINKAGE
Determine the ratio of genotypes in offspring in a dihybrid crossing of two diheterozygous organisms. Genes A and b, a and B are linked. Dominance is complete. Write your answer as a sequence of numbers in descending order.
Answer
Choose one, the most correct option. How many types of gametes are formed in the parent organism with the AaBb genotype in the case of linked inheritance in the absence of crossing over?
1) 1
2) 2
3) 3
4) 4
Answer
Choose one, the most correct option. When homozygous tomato plants with red (A) round (B) fruits and plants with yellow (a) pear-shaped (b) fruits in F2 are crossed, phenotypic splitting occurs in the ratio (color genes and fruit shape are located in different pairs of chromosomes)
1) 1:1
2) 3:1
3) 1:2:1
4) 9:3:3:1
Answer
1. All of the following characteristics, except for two, are used to describe the linked type of inheritance. Find two features that fall out of general list, and write down the numbers under which they are indicated.
1) genes located on the same chromosome are inherited together
2) phenotype splitting is observed in the ratio 9:3:3:1
3) the number of linkage groups is equal to the haploid set of chromosomes
4) genes located on different pairs of chromosomes are inherited independently
5) as a result of crossing over, gene recombination occurs
Answer
2. All of the following characteristics, except for two, are used to describe the linked inheritance of traits. Identify two characteristics that “fall out” of the general list, and write down the numbers under which they are indicated.
1) one gene determines the development of several traits
3) the number of linkage groups is equal to the number of pairs of chromosomes
4) non-allelic genes on the same chromosome are inherited together
5) the manifestation of a trait depends on the action of an environmental factor
Answer
All the laws below, except for two, are the laws of heredity of G. Mendel. Find two laws that “fall out” of the general list, and write down the numbers under which they are indicated.
1) uniformity of hybrids of the first generation
2) independent inheritance of traits
3) inheritance of sex-linked traits
4) splitting of signs
5) linked inheritance of traits
Answer
All but two of the following characteristics are used to describe a pea dihybrid cross with independent inheritance and complete dominance. Find two characteristics that "fall out" from the general list, and write down the numbers under which they are indicated.
1) the number of linkage groups is equal to the haploid set of chromosomes
2) splitting according to the phenotype occurs in a ratio of 9: 3: 3: 1
3) genes for different traits are on different chromosomes
4) formation different types gametes due to crossing over
5) four phenotypic classes of offspring are formed in the ratio 1:1:1:1
Answer
All the statements below, except for two, are the provisions of the chromosome theory of heredity. Identify two statements that “fall out” of the general list, and write down the numbers under which they are indicated.
1) the traits of the parents are inherited by the offspring
2) genes are located linearly on the chromosome
3) genes located on the same chromosome are inherited linked
4) non-allelic genes are inherited independently
5) gene linkage is disrupted as a result of crossing over
Answer
© D.V. Pozdnyakov, 2009-2019
What formula is used to determine the number of phenotypes in the offspring during splitting?
To determine, the formula 2 n is used, in which n is the number of pairs of allelic genes.
If it happens monohybrid cross, "parents", endowed with a difference in one pair of traits (Mendel experimented with yellow and green peas), in the second generation they give two phenotype(2 1). At dihybrid crossing they differ in two pairs of traits and, accordingly, produce four phenotypes in the second generation (2 2).
In exactly the same way, the number of phenotypes obtained in the second generation is calculated by the method trihybrid crossing- eight phenotypes will appear (2 3).
What formula is used to determine the number of different types of gametes in heterozygotes?
This number is also calculated by the formula (2 n). However, n in this case is the number of gene pairs in the heterozygous state. On the use of this formula, problems are built in the Unified State Examination in biology and the internal exam of Moscow State University.
What formula is used to determine the number of genotypes in the offspring during splitting?
The formula 3 n is applied here, where n is the number of pairs of allelic genes. If the cross is monohybrid, the splitting by genotype in F 2 occurs in a ratio of 1:2:1, that is, three different genotypes are formed (3 1).
With dihybrid crossing, 9 genotypes (3 2) arise, with trihybrid - 27 genotypes (3 3).
Do you want to pass the exam perfectly? Click here -1) population-species
2) organismic
3) biogeocenotic
4) molecular
The infusoria shoe represents both the cellular level of life organization and
1) molecular
2) organismic
3) specific
4) biocenotic
What research is difficult in humans due to the slow change of generation and small offspring
1) anatomical
2) physiological
3) histological
4) genetic
4. In a DNA molecule, the number of nucleotides with guanine is 30% of the total. How many nucleotides with thymine are in this molecule?
Foreign proteins that enter the human body bind, forming complexes with
1) antigens
2) platelets
3) antibodies
4) antibiotics
Single cell animal cell
1) does not have an endoplasmic reticulum
2) creates organic substances from inorganic
3) has vacuoles with cell sap
4) performs all the functions of a living organism
The daughter organism retains the greatest similarity with the parent during reproduction.
1) parthenogenesis
2) sexually
3) using seeds
4) budding
How many phenotypic groups are formed when two heterozygotes are crossed?
3) twelve
4) sixteen
The essence of the phenomenon of heterosis used in breeding is
1) a multiple increase in the number of chromosomes
2) change in the gene pool of a variety or breed
3) the transition of many genes to a homozygous state
4) heterozygosity of hybrids
Which of the following representatives of the kingdom of fungi does not form mycelium?
1) penicillium
4) boletus
Task 2. "Yes" or "No"?
Remember who are tunicates And lancelets , what systematic groups do they belong to? What morphological features or biological features are present ("Yes") or absent ("No") in these groups. Fill in the table cells.
Task 3. Circles!
Consider the presented drawings, concentric circles are clearly visible on them. Answer the questions.
Questions:
1. What is shown in the pictures?
2. Are they similar or homologous structures?
3. How are they formed? (1 offer)
4. What are the reasons for the similarities? (1-2 sentences)
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Task 4. Biological tasks.
Read the conditions carefully and solve the biological problems. Write down in detail: given, decision, answer.
1. Average bee family in summer it has 70 thousand bees and collects 130 kg of honey per season. How much honey does each worker bee produce, considering that 1/14 of this family is busy with other things.
2. A lover of pigeons crossed a black male with hairy legs with the same female. And he got offspring - 15 chicks: 8 black with shaggy legs, 2 brown with shaggy legs, 4 black with bare legs and 1 brown with bare legs. The genes for the two traits are not linked.
Define:
1) genotypes of parents,
2) genotypes of offspring
3) the pattern of inheritance of traits.
Task 5. Photo question.
On this photo depicts a low island with correct form rings, composed of limestone. Almost its entire area is occupied by unusual lush greenery, outside there is a narrow sandy beach and a strip of shallow water, partially exposed during low tides. Answer the questions.
Questions:
1. What is the name of such formations?
2. What animals created this unique relief?
3. To what systematic group do they belong?
Task 6. Year of the monkey!
Chinese lunar calendar New Year celebrated on the second new moon after winter solstice which usually falls between January 21st and February 21st. 2016 new year corresponds to the year of the monkey!
You need to use your knowledge of monkey biology to come up with three original and tricky questions about biological features these animals and answer them.
Evaluation criteria:
1. Compliance with the task.
2. Biological literacy.
3. Originality.
4. Compliance with technical requirements.
Task 7. How it was ...
Answer the suggested questions:
1. What is your mood after completing all the tasks?
2. What was the most difficult and how did you overcome the difficulties?
3. What can you praise yourself for?
Try to make the answers to the questions interesting for other participants to read. You can write answers in any genre. It can be a story, a note, a fairy tale, a poem, etc.
Evaluation criteria:
· Reflection is not provided - 0 points.
· Reflection was made for this competition and is a formal answer to questions that are not related to each other - 1 point.
· Reflection was made for this competition and is the author's detailed answers to questions - 2 points.
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For clarification genotypes according to splitting in the offspring, it should be taken into account that when two diheterozygotes are crossed in the offspring, phenotypic splitting is observed in the ratio of 9:3:3:1, and for each individual trait, the phenotype ratio is 3:1. When mating homozygotes for each trait, the law of uniformity is observed. When analyzing crosses of diheterozygotes, four classes of phenotypes are present in the offspring in equal amounts, and the ratio of phenotypes for each trait is 1:1.
Task 4-11
In a figured pumpkin, the white color of the fruit (W) dominates over yellow (w), and the disc-shaped shape (D) over spherical (d). A pumpkin with white disc-shaped fruits was crossed with a pumpkin whose fruits were white and spherical. In the offspring it turned out:
- 3/8 white discs
- 3/8 white globular,
- 1/8 yellow disc
- 1/8 yellow globular.
Determine the genotypes of parents and offspring.
To solve this problem, you can consider each feature separately. Then:
- splitting by color 3:1, therefore, both plants were heterozygous (Ww);
- splitting in the form of 1: 1, therefore, a heterozygous individual (Dd) was crossed with a homozygous recessive (dd).
Indeed, one of the parent plants carried a recessive trait ( spherical shape fruits).
Thus, the genotype of the first individual is WwDd; the second genotype is Wwdd. Crossing analysis confirms the decision and reveals the genotypes of the offspring.
Crossing scheme
Task 4-12
In chickens, the pea-shaped crest dominates the leaf-shaped one, and the feathered legs over the bare ones. From a group of genetically homogeneous chickens with leaf-shaped combs and feathered legs, when crossed with a rooster with a pea-shaped comb and bare legs, the following offspring were obtained: with a pea-shaped comb and feathered legs - 59, with a pea-shaped comb and bare legs - 72, with a leaf-shaped comb and feathered legs - 63, with a leaf-shaped crest and bare legs - 66. Determine the genotypes of parents and offspring.
Task 4-13
In Drosophila, the gray color of the body dominates over the black, and the normal shape of the wings over the twisted one. When gray flies with normal and twisted wings were crossed, one quarter of the offspring had a black body. Approximately half of all daughter individuals had normal wings, and half had twisted wings. What are the genotypes of the parents?
Task 4-14
In pigs, white bristles dominate over black, and the presence of earrings over their absence. Determine the genotype of a white boar with earrings:
- if when mating it with any sows, white offspring with earrings are born;
- if mating another such boar with black sows without earrings, 50% of white piglets with earrings and 50% of black piglets with earrings are born.
Task 4-15
In wheat, awnlessness (A) dominates over awn (a), and the red color of the ear (B) over white (b). Plants of an awnless red-eared variety, when crossed with wheat of an awned white-eared variety, gave:
- 1/4 boneless red-eared,
- 1/4 boneless whiteheads,
- 1/4 spinous red-eared,
- 1/4 spinous white-haired.
Determine the genotypes of the original plants. Does this crossing correspond to the analyzed one?
Task 4-16
In a figured pumpkin, the white color of the fruit (W) dominates over the yellow (w), and the disc-shaped shape of the fruit (D) over the spherical (d). By crossing two plants with white disc-shaped fruits, 11 plants with yellow disc-shaped and 36 with white disc-shaped fruits were obtained. Determine the most probable genotype of the original plants.
Task 4-17
In Datura, the purple color of the flowers dominates over the white, prickly seed pods over the smooth ones. From crossing Datura with purple flowers and smooth boxes with a plant having white flowers and prickly boxes, 320 plants with purple flowers and prickly boxes and 423 with purple flowers and smooth boxes were obtained. What are the genotypes of the parent organisms and offspring?
Task 4-18
In chickens, the black color of plumage dominates over red, the presence of a crest - over its absence. The genes encoding these traits are located on different pairs of chromosomes. A red rooster with a comb is crossed with a black hen without a comb. Numerous offspring have been obtained, half of which have black plumage and crest, and half have red plumage and crest. What are the most likely genotypes of the parents?
Task 4-19
Normal growth in oats dominates over gigantism, early maturity - over late maturity. The genes for both traits are located on different autosomes. 22372 plants were obtained from crossing early ripe plants of normal growth. Of these, 5593 turned out to be gigantic, and the same number were late-ripening. Determine how many plants were obtained that simultaneously have signs of late maturation and giant growth.
According to the obtained relations, splitting occurred:
- by height - 5593:16779 (22372 - 5593),
- by maturity - 5593:16779 (22372 - 5593),
that is, for both traits, splitting occurred in a ratio of 1: 3, therefore, individuals heterozygous for both pairs of genes were crossed. In dihybrid crossing of diheterozygotes, the number of individuals with two recessive traits is 1/16.
This means that the number of late-ripening giant plants is equal to 22372/16, which is approximately 1398 (the methodological error of the authors of the problem is that very accurate figures are given, and Mendel's laws are statistical in nature).
Task 4-20
Tomato fruits are red and yellow, smooth and fluffy. The red gene is dominant, the fluffy gene is recessive. Both pairs are on different chromosomes. Of the tomatoes harvested on the collective farm, there were 36 tons of smooth red and 12 tons of red fluffy ones. How many yellow fluffy tomatoes will be in the collective farm crop if the source material was heterozygous for both traits?
Task 4-21
In phlox, the white color of flowers is determined by the W gene, cream - w; flat corolla - S, funnel-shaped - s. A phlox plant with white funnel-shaped flowers is crossed with plants that have cream flat flowers. Of the 76 offspring, 37 have white flat flowers, 39 are cream flat. Determine the genotypes of the original plants.
Task 4-22
In tomatoes, the purple color of the stem is dominant over the green. Dissected leaves are controlled by a dominant gene, while entire leaves are recessive. When crossing two varieties of tomato, one of which had a purple stem and a dissected leaf, the other had a green stem and a dissected leaf, the following offspring was obtained:
- 350 plants with a purple stem and a dissected leaf;
- 112 - with a purple stem and a whole leaf;
- 340 - with a green stem and a dissected leaf;
- 115 - with a green stem and a whole leaf.
What are the most likely genotypes of the parent plants?
