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Science Year 9 Exploring Science > 9A > Flashcards

Flashcards in 9A Deck (22)
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1

Give an adaptation of an egg cell

It's jelly coat only allows a single sperm cell to enter.

2

Give an adaptation of a sperm cell

Has a long tail to make it travel faster or has a streamlined shape

3

Name one recessive allel

Blue eyes, green eyes, blonde hair, or ginger hair

4

Explain the purpose of a punnett square

To find the probability of a certain characteristic getting passed on to the off-spring

5

Name an example of an environment characteristic

Skin colour (tan), length of hair, or accents

6

Define genetic information

The instructions, carried by the genes, that control you characteristics

7

Define characteristics

The features of an organism

8

Explain the role of a male gamete

To fuse two of the nuclei and fertilise the egg cell

9

Define cell division

When a cell grows in size and splits into two. Cells increase their numbers using cell division.

10

What is formed when a fertilised egg goes through cell division?

It forms an embryo

11

What is the difference between inherited and environmental characteristics?

The inherited characteristics are passed on from parents and the environment controls the environmental characteristics.

12

What would be the probability for a child of a parent with blue eyes and a parent with brown eyes and a recessive allel for blue eyes, be to get blue eyes?

50% for blue eyes

13

Define genotype and phenotype

Genotype: The genes that determine what the phenotype of an organism will be. Phenotype: The physical characteristics of an organism

14

Why does a person have brown eyes if they also carry an allel for blue eyes?

Because brown eyes are a dominant allel so the blue eyes will not have an effect as they are a recessive allel.

15

Define homozygous and heterozygous

Homozygous: When both of the genes are the same type. Heterozygous: When the genes are different from each other.

16

If a person has blue eyes what type of genes would they have? Heterozygous or Homozygous?

Homozygous because blue eyes are a recessive allel and show only when the genes are both the same.

17

Give the four steps of Selective Breeding

Firstly, the characteristics which are important are decided. Then the parents that show these characteristics are chosen. Next the best off-spring from the parents are selected to breed with the next generation. Finally the process is continuously repeated.

18

Define natural selection

A process founded by Charles Darwin which states that over a long period of time when species evolved, the fittest survive while the weakest eventually died off.

19

What are some desirable characteristics in animals?

Gentle, produce a lot of food, immune to certain diseases, etc.

20

Describe the process of cloning mammals.

The nucleus of an egg cell is fused with a cell of the mammal getting cloned and then cell division happens forming an embryo. The embryo is then implanted into the mammal that the nucleus came from.

21

Give an argument for and against genetic modifications.

There is too little information about the long-term effects of altering DNA(Against). It offers the prospect of cures for currently incurable disease(For). Etc.

22

Name some enviormental factors that might effect characteristics.

The climate of the environment, the proteins and vitamins that can be provided in that environment, the people in that environment, etc.