Unit 2 Test Flashcards
Specialised Cells
- sperm cell
-egg cell - red blood cell
- muscle cell
- root hair cell
- neurons
Importance of cell specialisation
- Diversity and efficiency
- Increase in complexity
- survival and evolution
Sperm cell
Nucleus - haploid- controls the activity of the cell
Acrosome- found in the head -digestive enzyme that allows penetration.
Mid section- contains lots of mitochondria
Tail- allows sperm to move
Egg cell
Nucleus- haploid- controls cell activity
Large cytoplasm - provides nourishment to fertilised egg
Zone pellucida- protects the egg.
Corona radiata- external layer of cells that support and provide nourishment to egg.
RBC - erythrocytes
- Oxygen transport
- flat disk shaped cells indented in the centre
- biconcave shape
- LSA for diffusion large surface area to volume ratio
- thinness of cell allows oxygen to diffuse rapidly between the exterior and innermost regions of cell
WBC
- Specialised cells that form part of the immune system.
- WBC’s are different one to their roles of fighting infection.
- unlike RBC, WBC are nucleated
- there are 4 types of WBC
Types of WBC
Neutrophils- make up most WBC and act as first line of defence.
Lymphocytes - involved in immune response. ‘Remembers’ the pathogen alerts body if it returns
Monocytes - largest type of WBC and transform into macrophages to consume pathogens or dead cells
Eosophils and basophils - participate in allergy response and parasite infections.
Upper epidermis
Adaptation - thin /transparent.
Purpose- allows light to pass through.
Palisade mesophyll
Adaptation-lots of chloroplasts
Purpose-for efficient photosynthesis
Spongy mesophyll
Adaptation- air sacs
Purpose- gases diffuse in and out
Lower epidermis
Adaptation - stomata
Purpose - Gases diffuse in and out.
