Bio paper 1 Exam Questions Wrong Answers Flashcards
Explain the advantages of red blood cells passing through a capillary one at a time? (3marks)
- B1 - cell structure
More oxygen is released to tissues/ more oxygen taken up from lungs.
Shorter distance (for exchange)
What domain are fungi classified in?
eukaryota
what are 5 types of evidence used to classify living things?
- 3 marks
- DNA analysis
- studies of internal/ cell structure with electron microscopes
- chemical analysis
- comparison of biochemical processes
- studies of evolutionary relationships
give one way the nucleus of the sperm is different to the nucleus of the body cells?
has half the number of chromosomes
suggest why antibiotics that disrupt the bacterial cell membrane often cause more side effects in humans compared with antibiotics that disrupt bacterial cell walls
- 1 mark
human cells have no cell wall
some people think that governments should pay drug manufacturers to develop new antibiotics.
suggest why
- 3 marks
- antibiotics are being developed at a slower rate than the emergence of new resistant strains
- resistant strains means we cannot treat (common) infections
- reduce (future) cost of antibiotic resistance infections
what is the function of WBCs? 1 mark
fight/ingest/kill bacteria/viruses/ microobes
why is it important for the nerve cell to detect stimuli?
- 3 marks
- to react/ respond to the surroundings
- avoid dangers/ protect the body
- to coordinate behaviour/ process information
what controls the rate of chemical reacrions
explain the significance of the nucleus in determining the characteristics of the offspring?
contains chromosomes/ genes/ DNA (1)
which contribute half the genes to the offspring (1)
describe how nitrate ions are used in a plant to help the plant grow?
- 3 marks
nitrate ions are used with glucose (1)
to form amino acids (1)
which are used to synthesise proteins needed for growth (1)
A plant cell is put into water and swells up, explain why.
- 3 marks
water enters the cell (1)
by osmosis/diffusion (1) through a partially permeable membrane (1)
the genetic material is arranged differently in cells of bacteria compared with animal and plant cells, describe 2 differences.
- only one chromosomes
- circular
- may have plasmids
- not in a nucleus
why is it necessary to absorb some food molecules by active transport?
- 1 mark
against a concentration gradient
suggest why epithelial cells have many mitochondria?
active transport requires energy from from respiration
explain how releasing sterile mosquitos reduces the spread of malaria?
- 2 marks
reduces breeding/ prodction in mosquitos (1) so fewer mosquitos bite people/ fewer mosquitos pass on pathogen/protist (1)
what is the function of haemoglobin/ red pigment?
- 2 marks
carries oxygen (1) from lungs to tissues (1)
explain one way sieve tubes cells are specialised for their function?
- 2 marks
have pored in the end walls (1) so dissolved sugars can move from cell to cell (1)
or
they have no nucleus/ few sub-cellular structures (1) to maximise space for movement of dissolved sugars
describe why it is important for dissolved sugars to be moved both upwards and downwards in a plant.
- 3 marks
sugars are made in leaves by photosysnthesis (1)
all cells/ tissues need sugar for respiration (1)
sugars are transported ti meristems for growth/ cell division/ mitosis
or
sugars are transported for storage as starch/ fat/ oil (1)
explain how cell enlargement is part of the growth process for a baby? (3)
- cells have to get bigger
2.cells have to mature to divide - cells which are bigger take up more space
why is cell specialisation important for the development and growth of a baby?
- babies need difference cells that have different functions
- specialised cells undergo mitosis to grow further cells
give one feature of the cell wall that allows the cell to become turgid?
cell is strong/ elastic
explain why single- celled organisms like algae do not need complex structures for gas exchange? (3 marks)
cell has larger SA: Vol ratio (1 mark)
short diffusion distance (1 mark)
diffusion via cell membrane is sufficient or flow of water maintains concentration gradient ( 1 mark)
explain why translocation is important in plants?
(2 marks)
sugars are made in leaves (1 mark)
so they need to be moved to other parts of the plant for respiration/ growth (1 mark)
explain why active transport is important in root hair cells?
( 2 marks)
for movement of minerals / ions ( 1 mark)
against their concentration gradient (1 mark)
what is the function of mitochondria? (2 marks)
To transfer energy for use (1) by aerobic respiration (1)
give 3 features of the plant and how it helps the plant to absorb mineral ions from the soil.
- thousands of root hairs —> large SA
- many mitochondria –> aeorbic respiration gives/ releases energy
- many of the cells in the root store starch –> starch is an energy source/ store (for active transport)
decribe 4 difference between bacteria cell and plant cell? (7)
- bacteria cell does not have mitochondria
- bacteria cell is smaller than plant cell
- bacteria cell does not have chloroplasts
- bacteria cells may have plasmids
- cell wall within bacteria cell is not made of cellulose
- bacteria cell does not have a large/ permanent vacuole
- bacteria cell has smaller ribosomes
explain how vaccinating chickens reduces the number of cases of salmonella food poisoning?
few bacteria/ pathogens in chicken/food (1) so fewer bacteria ingested by humans (1) /so fewer toxins produced
why is the number of cases of salmonella food poisoning higher in summer than in winter?
(1 mark)
warmer weather so bacteria reproduces faster