Question

14 4 Points Which part of the brain integrates sensory inputs and transmits them to the cerebral cortex? O brainstem O hypothalamus thalamus

Answer 1

14. The part of the brain that integrates sensory inputs and transmits them to the cerebral cortex is Thalamus.

The cerebrum wraps around a structure called the thalamus. The thalamus is the "relay centre" of the cerebral cortex. It means sensory messages reaching the brain must pass through the thalamus in order to be sensed consciously. Similarly, all motor messages delivered through the brain must pass through the thalamus. Limited sensory awareness of pain, temperature, touch and pressure is provided by the thalamus. Hence, thalamus acts as a major coordinating centre for sensory and motor signalling.

17. The above statement is false.

Within few hours after fertilization, the zygote begins a series of mitotic divisions known as cleavage and forms 2, 4, 8, 16 daughter cells called blastomeres. The embryo with 8 blastomeres is called morula. The cells of morula continue to divide and transforms into blastula or blastocyst as it moves further into the uterus. A blastocyst is a ball of cells with a large, fluid-filled cavity called blastocoel. The blastomeres in the blastocyst are arranged into an outer layer called trophoblast and inner mass of cells (attached to trophoblast) called the inner cell mass. Trophoblast or trophoectoderm does not take part in the formation of embryo proper. It forms the fetal portion of the placenta which provides food to the developing embryo. Cells of inner mass are destined to form the body of the developing embryo, because it has pluripotent stem cells. The pluripotent stem cells derived from the inner cell mass of blastocyst differentiate to generate primitive ectoderm, which ultimately differentiates into three primary germ layers namely, ectoderm, endoderm and mesoderm during gastrulation. So the cells derived from blastula or blastocyst are pluripotent.

Hence, the statement is false.