Biology June Exams

Question 1

how does a prokaryote differ from a eukaryote

Answer 1

a prokaryote has a flagella whereas a eukaryote does not. Prokaryotes also do not have a neucleus

Question 2

what are the sub-cellular structures of animal cells?

Answer 2

-nucleus
-cytoplasm
-cell membrane
-mitochondria
-ribosomes

Question 3

what is a nucleus

Answer 3

contains genetic material that controls the activities of the cell. the genetic material is arranged into chromosomes

Question 4

what is the cytoplasm

Answer 4

gel-like substance where most of the chemical reactions happen

Question 5

what is the cell membrane

Answer 5

holds the cell together and controls what goes in and out

Question 6

what is the mitochondria

Answer 6

these are where most of the reactions for respiration take place. respiration transfers energy that the cell needs to work

Question 7

what are the ribosomes

Answer 7

these are involved in translation of genetic material in the synthesis of proteins

Question 8

what subcellular structures do plant cells have?

Answer 8

-nucleus
-cytoplasm
-cell membrane
-mitochondria
-ribosomes
-cell wall
-large vacuole
- chloroplasts

Question 9

what is the cell wall

Answer 9

made of cellulose. it supports the cell and strengthens it

Question 10

what is the vacuole

Answer 10

contains cell sap, a weak solution of sugar and salts. it maintains the internal pressure to support the cell

Question 11

what is the chloroplasts

Answer 11

these are where photosynthesis occurs, which makes food for the plant. they contain a green substance called chlorophyll

Question 12

what subcellular structures do bacteria cells have

Answer 12

-chromosomal DNA
-ribosomes
-cell membrane
-plasmid DNA
-flagellum

Question 13

what is the chromosomal DNA

Answer 13

controls the cell’s activities and replication. it floats free in the cytoplasm

Question 14

what is the plasmid DNA

Answer 14

small loops of extra DNA that aren’t part of the chromosome. Plasmids contain genes for things like drug resistance, and can be passed between bacteria

Question 15

what is the flagellum

Answer 15

a long, hair-like structure that rotates to make the bacterium move. it can be used to move the bacteria away from harmful substances like toxins and towards beneficial things like nutrients or oxygen

Question 16

define haploid

Answer 16

23 chromosomes (sex cells)

Question 17

define diploid

Answer 17

23 pairs of chromosomes

Question 18

why is a neurone cell a specialised cell

Answer 18

long length for transmitting signals over long distances

Question 19

why is a palisade cell a specialised cell

Answer 19

transparent, regular shaped cells with chloroplasts

Question 20

why is a red blood cell a specialised cell

Answer 20

large surface area for absorbing oxygen

Question 21

why is a root hair cell a specialised cell

Answer 21

long and thin to increase surface area, take water up into plant cells

Question 22

why is the egg cell a specialised cell

Answer 22

contains large food store and genetic material to grow and develop

Question 23

why is a sperm cell a specialised cell

Answer 23

tail which allows cell to swim

Question 24

why is a xylem cell a specialised cell

Answer 24

hollow to carry water

Question 25

why is a ciliated epithelial cell a specialised cell

Answer 25

has tiny hairs to help move liquids

Question 26

what does resolution mean in microscopy

Answer 26

how well a microscope distinguishes between two points that are close together. A higher resolution means that the image can be seen more clearly and is more detailed.

Question 27

when was light microscopes invented

Answer 27

in the 1590s

Question 28

how do light microscopes work

Answer 28

by passing light through the specimen. they let us see things like nuclei and chloroplasts and we can also use them to study living cells

Question 29

when were electron microscopes invented

Answer 29

1930s

Question 30

how do electron microscopes work

Answer 30

they use electrons rather than light. they have a higher magnification and resolution than light, so they let us see smaller things in more detail like the internal structure of mitochondria and chloroplasts.

Question 31

what is the method of viewing a specimen using a microscope practical.

Answer 31

-take a thin slice of specimen -take a clean slid and using a pipette put one drop of water in the middle -use tweezers to add the specimen on the slide -add a drop of stain -place a cover slip at one end, holding it at an angle with a mounted needle and lower it -press down gently so no air bubbles are formed -clip the slide on the stage -select the lowest-powered objective lens -