Chapter 4 - Lesson 1 Flashcards Preview

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Flashcards in Chapter 4 - Lesson 1 Deck (25):
1

In single genes with 2 alleles, there is...

one dominant allele and one recessive allele

2

In single genes with multiple alleles, there are

3 or more forms of a gene code for a single trait.

3

________ is controlled by a gene with multiple alleles

Blood type

4

There are _____ main blood types

4

5

The 4 main blood types are

A, B, AB and O

6

_____ alleles control the inheritance of blood types

3

7

The allele for blood type A and B are

codominant

8

The allele for blood type O is

recessive

9

Some human traits show a large number of ________ because the traits are controlled by many genes.

phenotypes

10

Traits that is controlled by many genes are

height and skin color

11

Sex chromosomes are

one of 23 pair of chromosomes in each body. It carries genes that determine whether a person is male or female.

12

Sex chromosomes are the only chromosome pair that

do not always match

13

Both of the female's sex chromosomes are _____ chromosomes

X

14

Males have ________ chromosomes

X and Y

15

When a sperm cell with an X chromosome fertilizes an egg, the egg has

2 X chromosomes and will develop into a girl

16

When a sperm with a Y chromosome fertilizes the egg, the egg has

1 X chromosome and 1 Y chromosome and will develop into a boy

17

Genes on the X and Y chromosomes are often called

sex linked genes

18

Traits controlled by sex linked genes are called

sex linked traits (such as colorblindness)

19

Males are more likely than females to have a sex linked trait that is controlled by

a recessive allele

20

Colorblindness is a trait controlled by

a recessive allele on the X chromsome

21

A carrier is

a person who has one recessive allele for a trait and one dominant allele. A carrier of a trait controlled by a recessive allele does not have the trait, but can pass the trait to the offspring.

22

Many of a person's characteristics are determined by

an interaction between genes and the environment

23

An example of a characteristic that is affected by the environment is

height. Lack of protein, minerals and vitamins can prevent a person from growing as tall as possible.

24

________ can also affect human skills, such as playing a musical instrument.

Environmental factors. Musical instruction is an environmental factor for a musician.

25

Some human traits are controlled by

1. single genes with 2 alleles
2. single genes with multiple alleles
3. many genes that act together