B1h-variation And Inheritance Flashcards Preview

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Flashcards in B1h-variation And Inheritance Deck (31)
1

Where are chromosomes held?

In the nucleus

2

What is a gene?

A short length of a chromosome that controls inherited characteristics

3

How many chromosomes do body cells have?

46 (23 pairs)

4

How many chromosomes do gametes have?

23

5

What are alleles?

Different versions of the same gene

6

What are the causes of genetic variation?

-gamete formation
Making sperm and eggs
chromosomes shuffled

-fertilisation
Sperm and egg join to form a new cell with 46 chromosomes

-mutations
Changes to the genes

7

What human characteristics are a result of both environment and inheritance?

Intelligence
Body mass
Height

8

When are dominant alleles expressed?

When they are present

9

When are recessive alleles expressed?

When the dominant allele is absent

10

What is a monohybrid cross?

When you breed two organisms together to look at a characteristic thats controlled by one gene

11

What is homozygous?

Two identical alleles

12

What is heterozygous?

Two different alleles

13

What is a genotype?

The genetic makeup

14

What is a phenotype?

The characteristics expressed

15

What are some examples of inherited disorders?

Red green colour blindness
Sickle cell anaemia
Cystic fibrosis

16

What are inherited disorders caused by?

Faulty alleles, mostly recessive

17

What chromosomes do men have?

XY

18

What chromosomes do women have?

XX

19

What issues are raised by knowledge of inherited disorders in a family?

All family members tested?
Should someone have children if their at risk?
Should you terminate pregnancy if test is positive?

20

When are dominant alleles expressed?

When they are present

21

When are recessive alleles expressed?

When the dominant allele is absent

22

What is a monohybrid cross?

When you breed two organisms together to look at a characteristic thats controlled by one gene

23

What is homozygous?

Two identical alleles

24

What is heterozygous?

Two different alleles

25

What is a genotype?

The genetic makeup

26

What is a phenotype?

The characteristics expressed

27

What are some examples of inherited disorders?

Red green colour blindness
Sickle cell anaemia
Cystic fibrosis

28

What are inherited disorders caused by?

Faulty alleles, mostly recessive

29

What chromosomes do men have?

XY

30

What chromosomes do women have?

XX

31

What issues are raised by knowledge of inherited disorders in a family?

All family members tested?
Should someone have children if their at risk?
Should you terminate pregnancy if test is positive?