Question

1. Cats have 38 chromosomes in their somatic cells and use the Lygaeus mode of sex determination.

1. How many chromosomes does a cat receive from its father?           
2. How many autosomes are present in a cat gamete?                         
3. How many sex chromosomes are there in a cat sperm?                    

d. How many autosomes are there in a somatic cell of a female cat?

e. If a diploid cell contains 12 chromosomes, how many potentially genetically distinct gametes can be formed?

Answer 1

ANSWERS

a) CAT RECEIVE 19 CHROMOSOMES  FROM FATHER  

WHICH LEADS TO SEX DETERMINE THE KITTENS GENDER

• The other 18 pairs of chromosomes are known as autosomes.
• Each kitten gets two sex chromosomes, one from its mother and one from its father.
• If it has two X chromosomes it is a girl, and if it has an X and a Y chromosome, it is a boy.
• Since only boys have Y chromosomes, the mother always passes on an X chromosome to offspring, and the father's chromosome determines the kitten's gender.
• This is comparable to gender determination in humans.

b) The other 18 pairs of chromosomes are known as autosomes

c) SPERM CARRY 19 CHROMOSOMES ( IN THAT 18 CHROMOSOMES ARE AUTOSOMES AND REMAINING ONE IS SEX DETERMINING CHROMOSOME IN PROGENY)

When cells divide, the chromosomes are replicated via a process called mitosis. Each daughter cell gets 38 chromosomes just like the parent cell. The exception occurs during the creation of gametes: sperm and eggs. Instead of mitosis, reproductive cells use meiosis, which cuts in half, to 19, the number of chromosomes in the daughter cells. Thus when an egg is fertilized by a sperm, the two half-sets of chromosomes combine, and the resulting cells have the normal 38 chromosomes.

d) There are 38 chromosomes. 2 are X chromosomes. So, there are 36 autosomes. in female cat.