May 2023 SL Flashcards
Which molecule is a sugar?
HOCH2 O
H H
C
C
OH
H
C
C
OH
OH
H
Why is sweat a good coolant for the body?
Breaking H bonds between water molecules in sweat requires energy from body heat.
Which is an effect of protein denaturation?
Parts of the protein become linked together by hydrolysis.
What usually distinguishes DNA from RNA?
pentoses linked to phosphates pentoses linked to bases
Research has shown that the genetic code is not entirely universal. Which research finding has
shown this?
In some organisms the genetic code for mitochondria differs from the genetic code for
the nucleus.
This is a sequence of nucleotides from a section of mRNA.
AUGAAACGCACGCAG
From which DNA sequence has it been transcribed?
TACTTTGCGTGCGTC
Which gas produces most of the bubbles in bread dough?
Carbon dioxide
What is the process shown in this image?
Binary fission of a prokaryotic cell
What distinguishes prokaryotic cells and eukaryotic cells?
cell structure not compartmentalized cell structure compartmentalized
What can be deduced about a striated muscle fibre from both of these statements?
“A eukaryotic cell has one nucleus.”
“A striated muscle fibre has many nuclei.”
It is an exception to cell theory
The diagram is a model of one type of movement across a membrane.
What is this type of movement?
Facilitated diffusion
The statement relates to Pasteur’s experiments. What did this statement suggest?
Cells can only be formed by division of pre-existing cells.
What event occurs only in meiosis?
Random separation of homologous chromosomes
It is possible for two parents to have children with each of the four ABO blood groups.
What blood groups would the parents have?
A B
What is the effect of dominant alleles?
I. They mask the effect of recessive alleles.
II. They become more frequent than recessive alleles in a population.
III. They have a joint effect with recessive alleles when characteristics are co-dominant.
I only
Which technique separates proteins according to size?
Gel electrophoresis
Which category of organisms is correctly described by its method of nutrition and site of digestion?
consumer heterotrophic internal
What limits the length of food chains in an ecosystem?
The loss of energy between trophic levels
How can molluscs and platyhelminthes be distinguished?
Molluscs have a mouth and an anus but platyhelminthes do not
What is a feature of shorter wavelength visible radiation?
It includes violet light.
Which is a coniferophyte?
Which process promotes variation in a population?
The pictures show skeletons of a frog (Conraua goliath) and of a domestic rabbit
(Oryctolagus cuniculus).
What is the evolutionary relationship between X and Y?
What happens to starch in the small intestine?
