science year 9 T1

Question 1

outline what an organelle is?

Answer 1

an organelle is tiny structures inside of cells that allow the cell to function

Question 2

what is the cell membrane?

Answer 2

outer membrane of cell that controls movement in and out of the cell

Question 3

describe the cytoplasm?

Answer 3

a watery, jelly like mixture that fills the cell

Question 4

what is the nucleus and what does it contain?

Answer 4

control centre of the cell, regulates and directs all cellular function. contains genetic material

Question 5

what are the ribosomes?

Answer 5

microscopic factories that produce the proteins used by the body for growth and repair

Question 6

what is the mitochondria?

Answer 6

the powerhouse of the cell

Question 7

what is the golgi apparatus?

Answer 7

involved in the storing, packaging, modification and transport of molecules such as proteins

Question 8

what are alleles?

Answer 8

different forms or variations of a gene

Question 9

what is a gene?

Answer 9

a section of DNA that contains the instructions for a protein

Question 10

what are chromosones?

Answer 10

structures made up of DNA tightly coiled many times around proteins called histones

Question 11

what is a karyotype?

Answer 11

a map/picture of all the chromosomes in a cell, arranged in pairs (in size order)

Question 12

what is a genotype?

Answer 12

the genetic make-up of an individual. It can be the symbolic representation of the pair of alleles controlling a characteristic e.g. Bb, BB, Aa

Question 13

what is a phenotype?

Answer 13

the visible expression of a genotype e.g. blue eye

Question 14

what are dominant traits/phenotypes

Answer 14

require only one allele for the trait to show in the phenotype

Question 15

what are recessive traits/phenotypes?

Answer 15

require two copies of an allele before it shows in the phenotype

Question 16

what is a homozygous?

Answer 16

an organism which has two copies of the same allele (BB or bb) is said to be homozygous for that gene

Question 17

what is a heterozygous?

Answer 17

an organism that carries two different alleles (Bb) is said to be heterozygous for that gene

Question 18

what organelles do you find in plant cells?

Answer 18

nucleus, cell membrane, cytoplasm, mitochondria, vacoule, chloroplasts, cell wall

Question 19

what organelles are found in animal cells?

Answer 19

nucleus, cell membrane, cytoplasm, mitochondria, vacoule, ribosomes

Question 20

describe the functions of the organelles found in a plant cells

Question 21

what do the organelles found in animal cells do?

Question 22

whats the difference between animal and plant cells?

Answer 22

animal cells are round and irregular shaped, plant cells are more boxy and rectangular.

animal cells dont have a cell wall, plant cells do.

animal cells dont have a chloroplast, plant cells do.

Question 23

explain the function of DNA in living organisms

Answer 23

dna is like sets of instructions for your body, it tells it how to grow, work, and makes you who you are. it helps you body repair and make new cells.

Question 24

outline why DNA is universal

Answer 24

dna is universal because everyone has it, and they all use the same “code” to determine things.

Question 25

what is a DNA double helix and what is it made of?

Answer 25

its the shape of a DNA molecule. it looks like a twisted ladder. the "rails" of the ladder are made of sugar and phosphate molecules. the "steps" are made of pairs of nitrogen bases

Question 26

name the four nitrogenous bases in DNA and what the base-paring rules are

Answer 26

A, T, C, G A with T, C with G.

Question 27

explain the relationship between genes, chromosomes and DNA

Answer 27

DNA is the material that hold genes, genes are the instructions and chromosomes are how the DNA is organised in the cell

Question 28

what are autosomes?

Answer 28

autosomes are the 22 pairs of chromosomes that carry most of your genetic information

Question 29

what are sex chromosomes?

Answer 29

sex chromosomes are the chromosomes that determine your gender. females have XX and males have XY

Question 30

how many chromosomes are in a normal human cell and gametes?

Answer 30

In a normal human cell, there are 46 chromosomes, which are arranged in 23 pairs. This is called a diploid number because the cell has two sets of chromosomes (one from each parent). In gametes (sperm and egg cells), there are only 23 chromosomes, which is called a haploid number because they have only one set of chromosomes, half the number found in normal cells.