Science Review Topics 3-5

Question 1

Define DNA

Answer 1

DNA is your genetic code that determines all of your heritable traits.

Question 2

What does DNA stand for?

Answer 2

DNA stands for Deoxyribonucleic acid.

JAQUAN IT IS SPELT WITH A Y U DUMMY

Question 3

What is a chromosome?

Answer 3

A chromosome is a long piece of DNA that has been wound up.

JAQUAN IT IS CHROMOSOME NOT CHROMOSONE

Question 4

What does a gene do?

Answer 4

A gene is a small section of a chromosome that determines one of your heritable traits.

Question 5

Binary Fission

Answer 5

A single-celled organism reproduces by dividing
itself into two identical clones

Ex: unicellular organisms like amoebas and bacteria

Question 6

Budding

Answer 6

An organism reproduces by creating small “buds” that
grow into clones of the parent

Ex: yeast and coral

Question 7

Spores

Answer 7

Are seed-like structures that produce clones of the
parent organism

Ex: mushrooms and ferns

Question 8

Vegetative reproduction

Answer 8

Vegetative reproduction is when a plant makes
clones of itself.

Ex: runners, cuttings & tubers

Question 9

Describe the steps in animal sexual reproduction

Answer 9

Animal sexual reproduction begins with male and female gametes, the sperm and the egg. The egg is fertilized by the sperm and becomes a zygote. The zygote then divides many times to become an embryo.

Question 10

Female parts of a flower

Answer 10

Pistil (style, stigma, ovary, & ovule) – the female part that makes the ovule

Question 11

Male parts of the flower

Answer 11

Stamen (anther & filament) - the male part that makes the pollen

Question 12

What are the steps in plant reproduction?

Answer 12

1. Pollen is produced on the stamen of one plant
2. Pollen is transported to another flower
3. Pollen comes into contact with the pistil from another plant
4. Pollen makes a pollen tube to the ovule
5. Sperm travels down the tube and fertilizes the ovule

Question 13

Discrete variation

Answer 13

This means that there are only a few different forms of an inherited trait.
Ex: tongue rolling (can/cannot), sex (male/female), blood type (A, B, AB, O)

Question 14

Continuous variation

Answer 14

This means that there are many different forms of an inherited trait.
Ex: height, weight, hair colour

Question 15

Dominant traits

Answer 15

Characteristics that are always seen.

Question 16

Recessive traits

Answer 16

Characteristics that will only be seen if a dominant trait is not present.

Question 17

Mutations

Answer 17

Changes to your DNA

Question 18

Biotechnology

Answer 18

When humans change the DNA of an organism for our own benefit.

Question 19

Artifical Selection

Answer 19

When humans choose which males and females of a
species will reproduce.

Question 20

Mitosis

Answer 20

When your body makes identical copies of its cells for growth or repair.
- These body cells that divide for growth or repair
are called “somatic cells”

Question 21

Miosis

Answer 21

When your body makes specialized half cells for sexual reproduction.
- These half cells are called “gametes” (sperm/egg).
- When two half cells join, they create a whole cell!

Question 22

Nucleotides

Answer 22

The four molecules that form the inside of the ladder.

Nucleotides form in pairs:
Adenine (A) &Thymine (T)
Guanine (G) & Cytosine (C)